In the footer of most pages (including this one), click on the "Change Password" link. Further help is available in the PDF information sheet HERE
You need to contact the IDS office to to this. It is essential that they are informed of changes of email address, and they will update your account for the website. You may wish to use the "Contact Form" in the footer of this page.
Please send an email to the IDS office, or use the form on the Contact Us page. Or call the office on +44 1544 232 045